KR102111461B1 - Display device using semiconductor light emitting device and method for manufacturing the same - Google Patents

Abstract

A display device according to the present invention includes a substrate, a plurality of semiconductor light emitting elements formed and disposed on the substrate, and a first electrode disposed on the substrate and electrically connected to the semiconductor light emitting elements below the semiconductor light emitting element. , A second electrode electrically connected to the semiconductor light emitting elements above the semiconductor light emitting element, and a plurality of partition walls disposed on the semiconductor light emitting elements and disposed between the semiconductor light emitting elements, the substrate Is made of a light-transmitting material, characterized in that the width of the partition wall portion is narrower as it moves away from the substrate.

Description

DISPLAY DEVICE USING SEMICONDUCTOR LIGHT EMITTING DEVICE AND METHOD FOR MANUFACTURING THE SAME

The present invention relates to a display device and a manufacturing method, and more particularly, to a partition formed between semiconductor light emitting elements.

2. Description of the Related Art Recently, display devices having excellent characteristics such as thin and flexible have been developed in the field of display technology. On the other hand, the main commercialized displays are currently represented by LCD (Liguid Crystal Display) and AMOLED (Active Matrix Organic Light Emitting Diodes).

However, in the case of LCD, there is a problem that the reaction time is not fast and the implementation of flexible is difficult, and in the case of AMOLED, there are short-lived and poor mass production yield.

Meanwhile, a light emitting diode (LED) is a well-known semiconductor light emitting device that converts electric current into light. Starting with the commercialization of red LEDs using GaAsP compound semiconductors in 1962, information along with GaP: N series green LEDs It has been used as a light source for display images of electronic devices including communication devices. Therefore, a method of solving the above problems by implementing a display using the semiconductor light emitting device may be suggested.

A structure that excites light emitted from the semiconductor light emitting device by using a phosphor layer may be applied to the flexible display using the semiconductor light emitting device. In this case, the phosphor layer may be provided with a partition structure for preventing color mixing, but research on this is insufficient. Particularly, when a high-quality display is implemented using a semiconductor light-emitting device, the semiconductor light-emitting device should be small, but there are limitations.

One object of the present invention is to provide a display device having a new type of partition structure capable of preventing color mixing and a manufacturing method thereof.

One object of the present invention is to provide a display device having a new type of partition structure that allows luminance to be improved, and a method for manufacturing the same.

A display device according to the present invention includes a substrate, a plurality of semiconductor light emitting elements formed and disposed on the substrate, and a first electrode disposed on the substrate and electrically connected to the semiconductor light emitting elements below the semiconductor light emitting element. , A second electrode electrically connected to the semiconductor light emitting elements above the semiconductor light emitting element, and a plurality of partition walls disposed on the semiconductor light emitting elements and disposed between the semiconductor light emitting elements, the substrate Is made of a light-transmitting material, characterized in that the width of the partition wall portion is narrower as it moves away from the substrate.

In one embodiment, the second electrode may include a plurality of holes.

In one embodiment, the plurality of holes may be formed at a position overlapping the partition walls.

In one embodiment, the plurality of semiconductor light emitting devices are arranged in a plurality of columns, the first electrode is made of a plurality of electrode lines, and the semiconductor light emitting elements included in any one of the plurality of columns The semiconductor light emitting elements included in the other one of the plurality of columns may be electrically connected to different electrode lines.

In one embodiment, a plurality of electrode lines are arranged to be spaced a predetermined distance, and the partition walls may be arranged between the electrode lines.

In one embodiment, the semiconductor light emitting devices include first semiconductor light emitting elements that emit a first color and second semiconductor light emitting devices that emit a second color, and semiconductor light emitting devices that emit the same color are positioned adjacent to each other. In at least two rows can be arranged.

In one embodiment, the semiconductor light emitting device disposed in any one of the at least two columns and the semiconductor light emitting device disposed in the other may be electrically connected to different electrode lines spaced a predetermined distance apart.

In addition, the present invention comprises the steps of applying a photocurable material on a substrate, disposing a first mask on the upper side of the substrate, disposing a second mask on the lower side of the substrate, the upper side of the first mask and the first 2) irradiating light from each lower side of the mask to cure the photocurable material and removing uncured portions of the applied photocurable material to form partition walls, and the width of the partition walls Provides a method of manufacturing a display device characterized in that it becomes narrower as it moves away from the substrate.

In one embodiment, each of the first and second masks includes a light blocking region blocking light and a non-shielding region transmitting light, and at least a portion of the non-shielding region provided in the first mask and the second At least a portion of the non-shielding area provided in the mask may be disposed to overlap each other.

In one embodiment, in the curing of the photocurable material, the amount of light emitted from the lower side of the second mask may be greater than the amount of light emitted from the upper side of the first mask.

According to the present invention, since light is irradiated from both the upper and lower sides of the substrate, light can reach the position adjacent to the substrate. Through this, the present invention makes it possible to manufacture a partition wall having a structure in which the width increases as it approaches the substrate.

In addition, since the partition wall portion according to the present invention has an excellent light-shielding ability because all regions are formed with a reference width or higher, and reflects light emitted from the semiconductor light emitting device to the upper side of the substrate, it is possible to increase light extraction efficiency of the display device. .

1 is a conceptual diagram showing an embodiment of a display device using a semiconductor light emitting device of the present invention.
FIG. 2 is a partially enlarged view of part A of FIG. 1, and FIGS. 3A and 3B are cross-sectional views taken along lines BB and CC of FIG. 2.
4 is a conceptual diagram illustrating the flip-chip type semiconductor light emitting device of FIG. 3.
5A to 5C are conceptual views illustrating various forms of color in connection with a flip chip type semiconductor light emitting device.
6 is a cross-sectional view illustrating a method of manufacturing a display device using the semiconductor light emitting device of the present invention.
7 is a perspective view showing another embodiment of a display device using the semiconductor light emitting device of the present invention.
8 is a cross-sectional view taken along line DD of FIG. 7.
9 is a conceptual diagram illustrating the vertical semiconductor light emitting device of FIG. 8.
10 is a conceptual view showing a method of forming a partition wall by a conventional photocuring method.
11 is a conceptual view showing a method of forming a partition wall according to the present invention.
12 is a conceptual diagram showing a display device having a new structure.
13 is a cross-sectional view taken along line AA of FIG. 12.
14 is a cross-sectional view taken along line BB of FIG. 12.
15 is a conceptual diagram illustrating a modified embodiment of a display device according to the present invention.
16 is a cross-sectional view taken along line CC of FIG. 15.
17 is a cross-sectional view taken along line DD of FIG. 15.
18 is a cross-sectional view taken along line EE of FIG. 15.
19 is a conceptual diagram showing the shape of the partition wall according to the amount of light emitted from each of the upper and lower sides of the substrate.

Hereinafter, exemplary embodiments disclosed herein will be described in detail with reference to the accompanying drawings, but the same or similar elements are assigned the same reference numbers regardless of the reference numerals, and overlapping descriptions thereof will be omitted. The suffixes "modules" and "parts" for components used in the following description are given or mixed only considering the ease of writing the specification, and do not have meanings or roles distinguished from each other in themselves. In addition, in describing the embodiments disclosed in this specification, detailed descriptions of related known technologies are omitted when it is determined that the gist of the embodiments disclosed in this specification may be obscured. In addition, it should be noted that the accompanying drawings are only for easy understanding of the embodiments disclosed in the present specification, and the technical spirit disclosed in the present specification should not be interpreted as being limited by the accompanying drawings.

Also, it is understood that when an element, such as a layer, region, or substrate, is referred to as being “on” another component, it may be present directly on the other element or intermediate elements may be present therebetween. There will be.

Display devices described herein include mobile phones, smart phones, laptop computers, digital broadcasting terminals, personal digital assistants (PDAs), portable multimedia players (PMPs), navigation, and slate PCs. , Tablet PC, Ultra Book, digital TV, desktop computer. However, it will be readily appreciated by those skilled in the art that the configuration according to the embodiment described in the present specification may be applied to a device capable of display, even in a new product form developed later.

1 is a conceptual diagram showing an embodiment of a display device using a semiconductor light emitting device of the present invention.

According to the drawing, information processed by the control unit of the display apparatus 100 may be displayed using a flexible display.

The flexible display includes a display that can be bent, bendable, twistable, collapsible, and curlable by an external force. For example, the flexible display may be a display fabricated on a thin flexible substrate that can be bent, bent, folded, or rolled like paper, while maintaining the display characteristics of a conventional flat panel display.

In a state in which the flexible display is not bent (for example, a state having an infinite curvature radius, hereinafter referred to as a first state), the display area of the flexible display becomes a flat surface. In the first state, the display area may be curved in a state curved by an external force (for example, a state having a finite radius of curvature, hereinafter referred to as a second state). As shown in the figure, information displayed in the second state may be visual information output on a curved surface. This visual information is realized by independently controlling the light emission of sub-pixels arranged in a matrix form. The unit pixel refers to a minimum unit for realizing one color.

The unit pixel of the flexible display may be implemented by a semiconductor light emitting device. In the present invention, a light emitting diode (LED) is illustrated as one type of semiconductor light emitting device that converts electric current into light. The light emitting diode is formed to have a small size, and through this, it can serve as a unit pixel even in the second state.

Hereinafter, a flexible display implemented using the light emitting diode will be described in more detail with reference to the drawings.

FIG. 2 is a partially enlarged view of part A of FIG. 1, FIGS. 3A and 3B are cross-sectional views taken along lines BB and CC of FIG. 2, and FIG. 4 is a conceptual view showing the flip chip type semiconductor light emitting device of FIG. 3A, 5A to 5C are conceptual views illustrating various forms of color in connection with a flip chip type semiconductor light emitting device.

2, 3A, and 3B, a display device 100 using a passive matrix (PM) type semiconductor light emitting device is illustrated as a display device 100 using a semiconductor light emitting device. However, the example described below is also applicable to an active matrix (AM) type semiconductor light emitting device.

The display device 100 includes a first substrate 110, a first electrode 120, a conductive adhesive layer 130, a second electrode 140, and a plurality of semiconductor light emitting devices 150.

The first substrate 110 may be a flexible substrate. For example, to implement a flexible display device, the first substrate 110 may include glass or polyimide (PI). In addition, if it is an insulating and flexible material, for example, any of PEN (Polyethylene Naphthalate) and PET (Polyethylene Terephthalate) can be used. Further, the first substrate 110 may be either a transparent material or an opaque material.

The first substrate 110 may be a wiring substrate on which the first electrode 120 is disposed, and thus the first electrode 120 may be located on the first substrate 110.

According to the drawing, the insulating layer 160 may be disposed on the first substrate 110 on which the first electrode 120 is located, and the auxiliary electrode 170 may be positioned on the insulating layer 160. In this case, a state in which the insulating layer 160 is stacked on the first substrate 110 may be one wiring substrate. More specifically, the insulating layer 160 is an insulating and flexible material such as polyimide (PI, Polyimide), PET, PEN, etc., and is integrally formed with the first substrate 110 to form a single substrate. have.

The auxiliary electrode 170 is an electrode that electrically connects the first electrode 120 and the semiconductor light emitting device 150. The auxiliary electrode 170 is positioned on the insulating layer 160 and is disposed corresponding to the position of the first electrode 120. For example, the auxiliary electrode 170 has a dot shape and may be electrically connected to the first electrode 120 by an electrode hole 171 penetrating the insulating layer 160. The electrode hole 171 may be formed by filling a via hole with a conductive material.

Referring to these drawings, a conductive adhesive layer 130 is formed on one surface of the insulating layer 160, but the present invention is not limited thereto. For example, a layer performing a specific function is formed between the insulating layer 160 and the conductive adhesive layer 130, or the conductive adhesive layer 130 is disposed on the first substrate 110 without the insulating layer 160. It is also possible. In a structure in which the conductive adhesive layer 130 is disposed on the first substrate 110, the conductive adhesive layer 130 may serve as an insulating layer.

The conductive adhesive layer 130 may be a layer having adhesiveness and conductivity, and for this purpose, a conductive material and an adhesive material may be mixed in the conductive adhesive layer 130. In addition, the conductive adhesive layer 130 is flexible, thereby enabling a flexible function in the display device.

As such an example, the conductive adhesive layer 130 may be an anisotropic conductive film (ACF), an anisotropic conductive paste, a solution containing conductive particles, or the like. The conductive adhesive layer 130 allows electrical interconnection in the Z direction through the thickness, but may be configured as a layer having electrical insulation in the horizontal X-Y direction. Therefore, the conductive adhesive layer 130 may be referred to as a Z-axis conductive layer (however, hereinafter referred to as a 'conductive adhesive layer').

The anisotropic conductive film is a film in which an anisotropic conductive medium is mixed with an insulating base member, and when heat and pressure are applied, only a specific portion is conductive by the anisotropic conductive medium. Hereinafter, although it is described that heat and pressure are applied to the anisotropic conductive film, other methods are also possible for the anisotropic conductive film to be partially conductive. Such a method may be, for example, only one of the heat and pressure applied, or UV curing.

In addition, the anisotropic conductive medium may be, for example, conductive balls or conductive particles. According to the drawing, in this example, the anisotropic conductive film is a film in which a conductive ball is mixed with an insulating base member, and when heat and pressure are applied, only a specific portion has conductivity by the conductive ball. In the anisotropic conductive film, the core of the conductive material may be in a state containing a plurality of particles covered by an insulating film made of a polymer material, and in this case, a portion where heat and pressure is applied is destroyed by the insulating film, so that the core has conductivity. . At this time, the shape of the core is deformed to form a layer contacting each other in the thickness direction of the film. As a more specific example, heat and pressure are applied to the anisotropic conductive film as a whole, and an electrical connection in the Z-axis direction is partially formed by a height difference of a counterpart adhered by the anisotropic conductive film.

As another example, the anisotropic conductive film may be a state in which the insulating core contains a plurality of particles coated with a conductive material. In this case, the portion where heat and pressure is applied is deformed (pressed) to become conductive in the thickness direction of the film. As another example, a form in which the conductive material penetrates the insulating base member in the Z-axis direction and has conductivity in the thickness direction of the film is also possible. In this case, the conductive material can have a pointed end.

According to the drawing, the anisotropic conductive film may be a fixed array ACF (arranged array anisotropic conductive film) composed of conductive balls inserted into one surface of an insulating base member. More specifically, the insulating base member is formed of an adhesive material, and the conductive balls are intensively disposed on the bottom portion of the insulating base member, and when heat and pressure are applied from the base member, the conductive ball is deformed together with the conductive ball. Therefore, it has conductivity in the vertical direction.

However, the present invention is not necessarily limited to this, and the anisotropic conductive film is a form in which a conductive ball is randomly mixed into an insulating base member, or a plurality of layers and a conductive ball is disposed in one layer (double- ACF).

The anisotropic conductive paste is a combination of a paste and a conductive ball, and may be a paste in which conductive balls are mixed with insulating and adhesive base materials. Further, the solution containing conductive particles may be a solution containing conductive particles or nano particles.

Referring back to the drawings, the second electrode 140 is positioned on the insulating layer 160 spaced apart from the auxiliary electrode 170. That is, the conductive adhesive layer 130 is disposed on the insulating layer 160 on which the auxiliary electrode 170 and the second electrode 140 are located.

After forming the conductive adhesive layer 130 in the state where the auxiliary electrode 170 and the second electrode 140 are positioned on the insulating layer 160, the semiconductor light emitting device 150 is connected in a flip chip form by applying heat and pressure. In other words, the semiconductor light emitting device 150 is electrically connected to the first electrode 120 and the second electrode 140.

Referring to FIG. 4, the semiconductor light emitting device may be a flip chip type light emitting device.

For example, the semiconductor light emitting device includes a p-type electrode 156, a p-type semiconductor layer 155 on which the p-type electrode 156 is formed, an active layer 154 formed on the p-type semiconductor layer 155, and an active layer ( And an n-type semiconductor layer 153 formed on 154 and an n-type electrode 152 spaced apart from the p-type electrode 156 on the n-type semiconductor layer 153. In this case, the p-type electrode 156 may be electrically connected by the auxiliary electrode 170 and the conductive adhesive layer 130, and the n-type electrode 152 may be electrically connected by the second electrode 140.

Referring to FIGS. 2, 3A and 3B again, the auxiliary electrode 170 is elongated in one direction, and one auxiliary electrode may be electrically connected to the plurality of semiconductor light emitting devices 150. For example, the p-type electrodes of the left and right semiconductor light emitting elements centering on the auxiliary electrode may be electrically connected to one auxiliary electrode.

More specifically, the semiconductor light-emitting device 150 is pressed into the conductive adhesive layer 130 by heat and pressure, and through this, between the p-type electrode 156 and the auxiliary electrode 170 of the semiconductor light-emitting device 150. The portion and the portion between the n-type electrode 152 and the second electrode 140 of the semiconductor light emitting device 150 have conductivity, and the rest of the portion has no indentation of the semiconductor light emitting element and thus has no conductivity. As such, the conductive adhesive layer 130 not only couples between the semiconductor light emitting device 150 and the auxiliary electrode 170 and between the semiconductor light emitting device 150 and the second electrode 140 but also forms an electrical connection.

In addition, the plurality of semiconductor light emitting devices 150 constitute a light emitting device array, and a phosphor layer 180 is formed on the light emitting device array.

The light emitting device array may include a plurality of semiconductor light emitting devices having different luminance values. Each semiconductor light emitting device 150 constitutes a unit pixel and is electrically connected to the first electrode 120. For example, a plurality of first electrodes 120 may be provided, and the semiconductor light emitting devices may be arranged in, for example, several columns, and the semiconductor light emitting devices of each column may be electrically connected to any one of the plurality of first electrodes.

In addition, since the semiconductor light emitting elements are connected in the form of a flip chip, semiconductor light emitting elements grown on a transparent dielectric substrate can be used. Further, the semiconductor light emitting devices may be nitride semiconductor light emitting devices, for example. Since the semiconductor light emitting device 150 has excellent luminance, it is possible to configure individual unit pixels even with a small size.

According to the drawing, a partition wall 190 may be formed between the semiconductor light emitting devices 150. In this case, the partition wall 190 may serve to separate the individual unit pixels from each other, and may be integrally formed with the conductive adhesive layer 130. For example, the base member of the anisotropic conductive film may form the partition wall by inserting the semiconductor light emitting device 150 into the anisotropic conductive film.

In addition, if the base member of the anisotropic conductive film is black, the contrast ratio can be increased while the partition 190 has reflective properties without a separate black insulator.

As another example, a reflective partition wall may be separately provided as the partition wall 190. In this case, the partition wall 190 may include a black or white insulator depending on the purpose of the display device. When the partition wall of the white insulator is used, there may be an effect of increasing the reflectivity, and when the partition wall of the black insulator is used, the contrast property may be increased while simultaneously having reflective properties.

The phosphor layer 180 may be located on the outer surface of the semiconductor light emitting device 150. For example, the semiconductor light emitting device 150 is a blue semiconductor light emitting device that emits blue (B) light, and the phosphor layer 180 functions to convert the blue (B) light into a color of a unit pixel. The phosphor layer 180 may be a red phosphor 181 or a green phosphor 182 constituting individual pixels.

That is, a red phosphor 181 capable of converting blue light into red (R) light may be stacked on the blue semiconductor light emitting device 151 at a position forming a red unit pixel, and a position forming a green unit pixel In, a green phosphor 182 capable of converting blue light into green (G) light may be stacked on the blue semiconductor light emitting device 151. In addition, only the blue semiconductor light emitting device 151 may be used alone in a portion constituting a blue unit pixel. In this case, the red (R), green (G), and blue (B) unit pixels may form one pixel. More specifically, phosphors of one color may be stacked along each line of the first electrode 120. Therefore, one line in the first electrode 120 may be an electrode that controls one color. That is, along the second electrode 140, red (R), green (G), and blue (B) may be sequentially arranged, and through this, a unit pixel may be implemented.

However, the present invention is not necessarily limited to this, and instead of the phosphor, the semiconductor light emitting device 150 and the quantum dot (QD) are combined to implement red (R), green (G), and blue (B) unit pixels. have.

In addition, a black matrix 191 may be disposed between each phosphor layer to improve contrast. That is, the black matrix 191 may improve contrast of contrast.

However, the present invention is not necessarily limited thereto, and other structures for implementing blue, red, and green may be applied.

Referring to FIG. 5A, each semiconductor light emitting device 150 mainly includes gallium nitride (GaN), and indium (In) and / or aluminum (Al) are added together to emit a high output light emitting blue and various light. It can be implemented as a device.

In this case, the semiconductor light emitting devices 150 may be red, green, and blue semiconductor light emitting devices to form sub-pixels, respectively. For example, red, green, and blue semiconductor light emitting devices R, G, and B are alternately arranged, and red, green, and blue semiconductor light emitting devices provide red, green, and blue unit pixels. They form a single pixel, and a full color display can be realized through this.

Referring to FIG. 5B, the semiconductor light emitting device may include a white light emitting device W in which a yellow phosphor layer is provided for each individual device. In this case, a red phosphor layer 181, a green phosphor layer 182, and a blue phosphor layer 183 may be provided on the white light emitting element W to form a unit pixel. Further, a unit pixel may be formed using a color filter in which red, green, and blue are repeated on the white light emitting element W.

Referring to FIG. 5C, a structure in which a red phosphor layer 181, a green phosphor layer 182, and a blue phosphor layer 183 is provided on an ultraviolet light emitting device (UV) is also possible. As such, the semiconductor light emitting device can be used not only in visible light but also in ultraviolet light (UV) in all areas, and the ultraviolet light (UV) can be expanded into a form of a semiconductor light emitting device that can be used as an excitation source of the upper phosphor. .

Looking again at this example, the semiconductor light emitting device 150 is positioned on the conductive adhesive layer 130 to constitute a unit pixel in the display device. Since the semiconductor light emitting device 150 has excellent luminance, it is possible to configure individual unit pixels even with a small size. The size of the individual semiconductor light emitting device 150 may be 80 μm or less on one side, or may be a rectangular or square device. In the case of a rectangle, the size may be 20X80 µm or less.

In addition, even when a square semiconductor light emitting device 150 having a length of 10 µm is used as a unit pixel, sufficient brightness for forming a display device appears. Accordingly, for example, when the size of the unit pixel is a rectangular pixel having one side of 600 µm and the other side of 300 µm, the distance of the semiconductor light emitting device is relatively sufficiently large. Accordingly, in this case, it is possible to implement a flexible display device having HD image quality.

The display device using the semiconductor light emitting device described above can be manufactured by a new type of manufacturing method. Hereinafter, the manufacturing method will be described with reference to FIG. 6.

6 is a cross-sectional view illustrating a method of manufacturing a display device using the semiconductor light emitting device of the present invention.

Referring to this drawing, first, a conductive adhesive layer 130 is formed on the insulating layer 160 on which the auxiliary electrode 170 and the second electrode 140 are located. The insulating layer 160 is stacked on the first substrate 110 to form a single substrate (or wiring substrate). The wiring substrate includes a first electrode 120, an auxiliary electrode 170, and a second electrode 140. It is placed. In this case, the first electrode 120 and the second electrode 140 may be arranged in mutually orthogonal directions. In addition, in order to implement a flexible display device, the first substrate 110 and the insulating layer 160 may each include glass or polyimide (PI).

The conductive adhesive layer 130 may be implemented by, for example, an anisotropic conductive film, and for this purpose, an anisotropic conductive film may be applied to the substrate on which the insulating layer 160 is positioned.

Next, the second light emitting element 150 corresponding to the positions of the auxiliary electrodes 170 and the second electrodes 140 and on which the plurality of semiconductor light emitting elements 150 constituting individual pixels are located is positioned on the semiconductor light emitting element 150. ) Are arranged to face the auxiliary electrode 170 and the second electrode 140.

In this case, the second substrate 112 is a growth substrate for growing the semiconductor light emitting device 150, and may be a sapphire substrate or a silicon substrate.

When the semiconductor light emitting device is formed in a wafer unit, it can be effectively used in a display device by having a distance and a size capable of forming a display device.

Then, the wiring substrate and the second substrate 112 are thermocompressed. For example, the wiring substrate and the second substrate 112 may be thermocompressed by applying an ACF press head. The wiring substrate and the second substrate 112 are bonded by the thermocompression bonding. Due to the properties of the anisotropic conductive film having conductivity by thermal compression, only a portion between the semiconductor light emitting device 150 and the auxiliary electrode 170 and the second electrode 140 has conductivity, through which the electrodes and the semiconductor light emitting The device 150 may be electrically connected. At this time, the semiconductor light emitting device 150 is inserted into the anisotropic conductive film, and through this, a partition wall may be formed between the semiconductor light emitting device 150.

Then, the second substrate 112 is removed. For example, the second substrate 112 may be removed using a laser lift-off (LLO) method or a chemical lift-off (CLO) method.

Finally, the second substrate 112 is removed to expose the semiconductor light emitting elements 150 to the outside. If necessary, a transparent insulating layer (not shown) may be formed by coating silicon oxide (SiOx) or the like on the wiring substrate to which the semiconductor light emitting device 150 is coupled.

In addition, a step of forming a phosphor layer on one surface of the semiconductor light emitting device 150 may be further included. For example, the semiconductor light emitting device 150 is a blue semiconductor light emitting device that emits blue (B) light, and a red phosphor or a green phosphor for converting the blue (B) light into a color of a unit pixel emits the blue semiconductor. A layer may be formed on one surface of the device.

The manufacturing method or structure of the display device using the semiconductor light emitting device described above may be modified in various forms. As an example, a vertical semiconductor light emitting device may also be applied to the display device described above. Hereinafter, the vertical structure will be described with reference to FIGS. 5 and 6.

In addition, in the modified examples or embodiments described below, the same or similar reference numerals are assigned to the same or similar configurations as the previous examples, and the description is replaced with the first description.

7 is a perspective view showing another embodiment of a display device using the semiconductor light emitting device of the present invention, FIG. 8 is a cross-sectional view taken along the line DD of FIG. 7, and FIG. 9 is a conceptual view showing the vertical semiconductor light emitting device of FIG. to be.

Referring to these drawings, the display device may be a display device using a passive matrix (PM) type vertical semiconductor light emitting device.

The display device includes a substrate 210, a first electrode 220, a conductive adhesive layer 230, a second electrode 240, and a plurality of semiconductor light emitting devices 250.

The substrate 210 is a wiring substrate on which the first electrode 220 is disposed, and may include polyimide (PI) to implement a flexible display device. In addition, any insulating material and flexible material may be used.

The first electrode 220 is positioned on the substrate 210 and may be formed as an electrode having a long bar shape in one direction. The first electrode 220 may be formed to act as a data electrode.

The conductive adhesive layer 230 is formed on the substrate 210 on which the first electrode 220 is located. Like a display device to which a flip chip type light emitting device is applied, the conductive adhesive layer 230 is an anisotropic conductive film (ACF), anisotropic conductive paste, and a solution containing conductive particles (solution) ). However, the present embodiment also illustrates a case in which the conductive adhesive layer 230 is implemented by the anisotropic conductive film.

After the anisotropic conductive film is positioned in a state where the first electrode 220 is positioned on the substrate 210, when the semiconductor light emitting device 250 is connected by applying heat and pressure, the semiconductor light emitting device 250 is first The electrode 220 is electrically connected. At this time, the semiconductor light emitting device 250 is preferably disposed to be positioned on the first electrode 220.

As described above, the electrical connection is generated because heat and pressure are applied in the anisotropic conductive film, which is partially conductive in the thickness direction. Therefore, in the anisotropic conductive film, it is divided into a portion 231 having conductivity in the thickness direction and a portion 232 having no conductivity.

In addition, since the anisotropic conductive film contains an adhesive component, the conductive adhesive layer 230 implements not only electrical connection between the semiconductor light emitting device 250 and the first electrode 220 but also mechanical bonding.

As described above, the semiconductor light emitting device 250 is positioned on the conductive adhesive layer 230, thereby configuring individual pixels in the display device. Since the semiconductor light emitting device 250 has excellent luminance, it is possible to configure individual unit pixels even with a small size. The size of the individual semiconductor light emitting device 250 may be 80 μm or less in length on one side, or may be a rectangular or square device. In the case of a rectangle, the size may be 20X80 µm or less.

The semiconductor light emitting device 250 may have a vertical structure.

Between the vertical semiconductor light emitting devices, a plurality of second electrodes 240 disposed in a direction crossing the longitudinal direction of the first electrode 220 and electrically connected to the vertical semiconductor light emitting device 250 are positioned.

Referring to FIG. 9, the vertical semiconductor light emitting device includes a p-type electrode 256, a p-type semiconductor layer 255 formed on the p-type electrode 256, and an active layer 254 formed on the p-type semiconductor layer 255. ), An n-type semiconductor layer 253 formed on the active layer 254 and an n-type electrode 252 formed on the n-type semiconductor layer 253. In this case, the p-type electrode 256 located at the lower side may be electrically connected by the first electrode 220 and the conductive adhesive layer 230, and the n-type electrode 252 positioned at the upper side is the second electrode 240 to be described later. ). Since the vertical type semiconductor light emitting device 250 can arrange electrodes up and down, it has a great advantage of reducing the chip size.

Referring to FIG. 8 again, a phosphor layer 280 may be formed on one surface of the semiconductor light emitting device 250. For example, the semiconductor light emitting device 250 is a blue semiconductor light emitting device 251 emitting blue (B) light, and a phosphor layer 280 for converting the blue (B) light into a color of a unit pixel is provided. Can be. In this case, the phosphor layer 280 may be a red phosphor 281 and a green phosphor 282 constituting individual pixels.

That is, a red phosphor 281 capable of converting blue light into red (R) light may be stacked on the blue semiconductor light emitting device 251 at a position forming a red unit pixel, and a position forming a green unit pixel In, a green phosphor 282 capable of converting blue light into green (G) light may be stacked on the blue semiconductor light emitting device 251. In addition, only the blue semiconductor light emitting device 251 may be used alone in a portion constituting a blue unit pixel. In this case, the red (R), green (G), and blue (B) unit pixels may form one pixel.

However, the present invention is not necessarily limited thereto, and as described above in a display device to which a flip chip type light emitting device is applied, other structures for implementing blue, red, and green may be applied.

Looking again at the present embodiment, the second electrode 240 is positioned between the semiconductor light emitting elements 250 and is electrically connected to the semiconductor light emitting elements 250. For example, the semiconductor light emitting elements 250 may be arranged in a plurality of columns, and the second electrode 240 may be located between the columns of the semiconductor light emitting elements 250.

Since the distance between the semiconductor light emitting elements 250 constituting individual pixels is sufficiently large, the second electrode 240 may be positioned between the semiconductor light emitting elements 250.

The second electrode 240 may be formed as an electrode having a long bar shape in one direction, and may be disposed in a direction perpendicular to the first electrode.

In addition, the second electrode 240 and the semiconductor light emitting device 250 may be electrically connected by a connecting electrode protruding from the second electrode 240. More specifically, the connection electrode may be an n-type electrode of the semiconductor light emitting device 250. For example, the n-type electrode is formed as an ohmic electrode for ohmic contact, and the second electrode covers at least a portion of the ohmic electrode by printing or deposition. Through this, the second electrode 240 and the n-type electrode of the semiconductor light emitting device 250 may be electrically connected.

According to the drawing, the second electrode 240 may be positioned on the conductive adhesive layer 230. In some cases, a transparent insulating layer (not shown) including silicon oxide (SiOx) or the like may be formed on the substrate 210 on which the semiconductor light emitting device 250 is formed. When the second electrode 240 is positioned after the transparent insulating layer is formed, the second electrode 240 is positioned on the transparent insulating layer. Further, the second electrode 240 may be formed spaced apart from the conductive adhesive layer 230 or the transparent insulating layer.

If a transparent electrode such as ITO (Indium Tin Oxide) is used to position the second electrode 240 on the semiconductor light emitting device 250, the ITO material has a poor adhesion property with the n-type semiconductor layer. have. Therefore, the present invention has the advantage of not having to use a transparent electrode such as ITO by placing the second electrode 240 between the semiconductor light emitting devices 250. Accordingly, the light extraction efficiency can be improved by using a conductive material that is not limited to the selection of a transparent material and has good adhesion to the n-type semiconductor layer as a horizontal electrode.

According to the drawing, a partition wall 290 may be positioned between the semiconductor light emitting devices 250. That is, a partition wall 290 may be disposed between the vertical semiconductor light emitting devices 250 to isolate the semiconductor light emitting devices 250 constituting individual pixels. In this case, the partition wall 290 may serve to separate individual unit pixels from each other, and may be integrally formed with the conductive adhesive layer 230. For example, the base member of the anisotropic conductive film may form the partition wall by inserting the semiconductor light emitting device 250 into the anisotropic conductive film.

In addition, when the base member of the anisotropic conductive film is black, the contrast ratio can be increased while the partition 290 has reflective properties without a separate black insulator.

As another example, as the partition wall 190, a reflective partition wall may be separately provided. The partition wall 290 may include a black or white insulator depending on the purpose of the display device.

If the second electrode 240 is located directly on the conductive adhesive layer 230 between the semiconductor light emitting devices 250, the partition wall 290 is between the vertical semiconductor light emitting device 250 and the second electrode 240. Can be located between. Accordingly, individual unit pixels may be configured with a small size by using the semiconductor light emitting device 250, and the distance of the semiconductor light emitting device 250 is relatively large enough to replace the second electrode 240 with the semiconductor light emitting device 250. ), It is possible to implement a flexible display device having HD image quality.

Further, according to the drawing, a black matrix 291 may be disposed between each phosphor to improve contrast. That is, the black matrix 291 can improve contrast of contrast.

As described above, the semiconductor light emitting device 250 is positioned on the conductive adhesive layer 230, thereby configuring individual pixels in the display device. Since the semiconductor light emitting device 250 has excellent luminance, it is possible to configure individual unit pixels even with a small size. Therefore, a full color display in which unit pixels of red (R), green (G), and blue (B) form one pixel may be implemented by the semiconductor light emitting device.

On the other hand, in order to implement the above-described full color display, it is necessary to prevent color mixing between semiconductor light emitting elements that emit different colors, or to prevent light that is converted from different colors from being mixed. To this end, a partition wall for blocking light may be disposed between the semiconductor light emitting elements or between the phosphor layers.

The partition wall portion is mainly formed through a photo-curing method. When the partition wall portion is formed through photo-curing, the shape of the partition wall may not be uniform. Specifically, in the case of forming the partition through the photo-curing method, the width of the partition may decrease or increase along one direction. Since the light blocking performance of the partition wall portion may vary depending on the shape of the partition wall portion, the shape of the partition wall portion is very important.

The present invention provides a display device having a partition wall portion having excellent light blocking ability and light extraction ability, and a method for forming the partition wall portion.

First, a method for manufacturing the partition wall portion will be described.

10 is a conceptual diagram showing a method of forming a partition wall portion in a conventional photocuring method, and FIG. 11 is a conceptual diagram showing a method of forming a partition wall portion according to the present invention.

Referring to FIG. 10, the partition wall portion 320a is formed by curing a photocurable material. Here, the photo-curable material 320 is a material that is cured when irradiated with light. The wavelength of light for curing the photocurable material may vary depending on the type of the photocurable material, but the type of the photocurable material and the wavelength of light for curing the photocurable material are not limited herein.

According to the conventional method, the step of applying the photo-curable material 320 on the substrate 310 proceeds. The photocurable material applied on the substrate 310 may have fluidity, and achieves a state that can be easily removed by external force.

Thereafter, the step of disposing the mask 330 on the substrate 310 is performed. The mask 330 includes a light blocking area 331 that can block light. The rest of the area except for the light blocking area 331 is an area through which light can pass, and is called a non-light blocking area. When the substrate 310 and the mask 330 overlap, a portion of the substrate 310 overlaps with the light blocking region 331, and the other portion overlaps with a non-light blocking region of the mask 330.

When light is irradiated from the upper side of the mask 330, the light reaches only a portion of the substrate overlapping the non-shielding region. Accordingly, the photocurable material applied to a portion of the substrate overlapping the non-shielding region is cured. Thereafter, when the uncured photocurable material is removed, only the partition portion 320a having a predetermined shape remains.

In the case of forming the partition part in the above-described manner, the partition part having a form in which the width increases as it moves away from the substrate 310 is formed. This is because light irradiated from the upper side of the substrate is mostly absorbed at a position far from the substrate, and it is difficult to reach a position close to the substrate.

The partition wall portion 320a of the above-described form is difficult to have excellent light blocking ability and light extraction ability. Specifically, the partition wall portion must be formed to have a reference width or more in order to shield light, but at a position adjacent to the substrate, the partition portion is not formed to be larger than the reference width. For this reason, the possibility of light passing through the partition portion at a position adjacent to the substrate increases.

In addition, since the partition portion having a form in which the width increases as it moves away from the substrate reflects light emitted from the semiconductor light emitting device toward the substrate, the partition portion of the above-described shape is difficult to contribute to improving light extraction efficiency.

The present invention provides a method for preventing the partition wall portion from becoming smaller as the width of the substrate is closer.

Referring to FIG. 11, in the manufacturing method according to the present invention, a step of applying the photocurable material 320 on the substrate 310 is performed. In one embodiment, the photocurable material may include at least one of TiO ₂ and Al ₂ O ₃ having high reflectance, but is not limited thereto.

The substrate 310 may be made of a light transmissive material to allow light to pass through. Specifically, in the manufacturing method according to the present invention, light is irradiated from both the upper side and the lower side of the substrate 310. In order for the light irradiated from the lower side of the substrate 310 to reach the photocurable material 320, the substrate 310 must be made of a light transmissive material.

Meanwhile, before the photocurable material 320 is applied, semiconductor light emitting devices may be disposed on the substrate 310. However, the present invention is not limited thereto, and the photocurable material may be applied while the semiconductor light emitting device is not disposed on the substrate.

Next, a step of disposing a first mask 330a on the upper side of the substrate 310 and disposing a second mask 330b on the lower side of the substrate is performed. The order of arranging the first and second masks is not particularly limited.

Each of the first and second masks includes a light blocking area and a non-light blocking area. The first and second masks are disposed such that at least a portion of the non-shielding region of the first mask and at least a portion of the non-shielding region of the second mask overlap each other.

A partition wall is formed around a position where the non-shielding areas of the first and second masks overlap with each other. However, the non-shielding areas of each of the first and second masks do not need to completely overlap, and if necessary, the non-shielding areas of the first and second masks may have different shapes, areas, intervals, and the like. .

In the state where each of the first and second masks overlaps the substrate, a step of irradiating light from the upper side of the first mask and the lower side of the second mask is performed. Accordingly, a part of the photocurable material is cured.

At this time, the amount of light emitted from the upper side of the first mask is less than the amount of light emitted from the lower side of the second mask. That is, the amount of light emitted from the lower side of the substrate is greater than the amount of light emitted from the upper side of the substrate. Through this, the present invention can be made such that the width of the partition wall portion becomes thicker as it is adjacent to the substrate, and thinner as it is further away from the substrate.

Finally, a step of removing the uncured portion of the applied photocurable material is performed. Accordingly, a partition wall portion 320b is formed on the substrate.

According to the above-described manufacturing method, since light is irradiated from both the upper and lower sides of the substrate, light can reach the position adjacent to the substrate. Through this, the present invention makes it possible to manufacture a partition wall having a structure in which the width increases as it approaches the substrate.

Since the partition portion of the structure in which the width increases as it is closer to the substrate has an excellent light-shielding ability because all regions of the partition portion are formed above a reference width, and reflects light emitted from the semiconductor light emitting device to the upper side of the substrate, light extraction of the display device Efficiency can be increased.

Meanwhile, the above-described partition wall part may be manufactured through a separate mask, but may be manufactured using electrodes disposed on the substrate. Hereinafter, a display device including a partition wall manufactured using wiring electrodes disposed on a substrate will be described.

12 is a conceptual view showing a display device having a new structure, FIG. 13 is a cross-sectional view taken along line A-A of FIG. 12, and FIG. 14 is a cross-sectional view taken along line B-B of FIG. 12.

Referring to the drawings, a plurality of semiconductor light emitting elements 250 are disposed on the substrate 410. The substrate 410 may be made of a light transmissive material.

The semiconductor light emitting devices are electrically connected to the first electrode 420 and the second electrode 440.

The first electrode 420 is disposed to cover a part of the substrate 410 and is electrically connected to the semiconductor light emitting device 250 under the semiconductor light emitting device 250. For adhesion between the semiconductor light emitting device 250 and the first electrode 420, a conductive adhesive layer 421 may be formed between the semiconductor light emitting device 250 and the first electrode 420, but the conductive adhesive layer 421 ) Is not required.

The second electrode 440 is electrically connected to the semiconductor light emitting elements 250 above the semiconductor light emitting element 440. Meanwhile, the second electrode 440 may include a protrusion 441 overlapping the semiconductor light emitting device 250. The protrusion 441 minimizes the area where the semiconductor light emitting element and the second electrode 440 overlap, thereby improving light extraction efficiency of the display device.

Meanwhile, an insulating layer 430 may be formed between the first and second electrodes and between semiconductor light emitting elements. A portion of the second electrode 440 is disposed to cover the semiconductor light emitting device 250, and another portion is disposed to cover the insulating layer 430.

Meanwhile, a plurality of partition walls 460 are disposed above the semiconductor light emitting elements 250. The partition walls 460 are disposed between semiconductor light emitting elements disposed on the substrate 410. A fluorescent material may be filled between the partition walls 460. The partition walls 460 prevent mixing of light excited with different colors.

On the other hand, the width of the partition wall portions 460 becomes narrower as it moves away from the substrate. Through this, the partition walls 460 reflect light toward the side of the partition wall upward. Accordingly, the light extraction efficiency of the display device can be increased.

The first and second electrodes described above may be used as the second mask in the manufacturing method described in FIG. 11. Specifically, in a state in which the first and second electrodes, the semiconductor light emitting device, and the insulating layer are formed on the light transmissive substrate, a photocurable material is applied to the upper side of the substrate, and the mask overlaps the substrate. At this time, the mask is disposed only on the upper side of the substrate, and the mask is not disposed on the lower side of the substrate.

Thereafter, when light is irradiated on the upper and lower sides of the substrate, light is selectively irradiated by the mask on the upper side of the substrate, and light is selectively irradiated by the first and second electrodes on the lower side of the substrate. Specifically, the first and second electrodes are made of a metal having high reflectance. For this reason, light cannot be transmitted through the first and second electrodes. Since the first electrode does not cover the entire substrate, and the second electrode also does not cover the entire upper portion of the substrate, a part of the light irradiated from the lower side of the substrate passes through the first and second electrodes and the applied sight It can even reach Mars. That is, the first and second electrodes may serve as a mask.

13 and 14, the partition wall portion 460 formed by the above-described method is formed between the first and second electrodes. More specifically, each of the first and second electrodes forms a light-shielding region and a non-shielding region, wherein the partition wall portion 460 has a non-shielding region formed by the first electrode and a ratio formed by the second electrode. A light blocking region is formed in an overlapping region.

According to the present invention, since there is no need to align a separate mask under the substrate, it is possible to reduce process time and process cost for forming the partition.

By adjusting the shapes of the light blocking area and the non-light blocking area by the first and second electrodes, it is possible to manufacture various positions or various types of partition walls. Hereinafter, structures of the first and second electrodes for manufacturing various types of partition walls will be described.

15 is a conceptual view showing a modified embodiment of the display device according to the present invention, FIG. 16 is a cross-sectional view taken along the line CC of FIG. 15, FIG. 17 is a cross-sectional view taken along the line DD of FIG. 15, and FIG. It is a sectional view taken along line EE of 15.

Referring to the drawings, the second electrode 540 may include a plurality of holes 542. The plurality of holes 542 serves to widen the non-shielding region formed by the second electrode 540. Since light can be transmitted between the plurality of holes 542, the partition wall portion is formed to overlap the plurality of holes 542.

As described above, the present invention forms a plurality of holes in the second electrode to adjust the position, size, and the like of the partition.

Meanwhile, the present invention makes it possible to manufacture various types of partition walls through the first electrode. Specifically, the plurality of semiconductor light emitting elements 250 are arranged in a plurality of rows. Here, the first electrodes 420 are formed of a plurality of electrode lines, and the semiconductor light emitting elements included in any one of the plurality of columns and the semiconductor light emitting elements included in the other one of the plurality of columns are different. It is electrically connected to the electrode line.

Here, the plurality of electrode lines are arranged to be spaced a predetermined distance. The shape, area, and the like of the non-shielding region by the first electrode 520 may be adjusted by adjusting an interval between the plurality of electrode lines.

Since light is transmitted through the electrode lines to cure the photocurable material, the partition wall portion 560 may be formed between the plurality of electrode lines.

Meanwhile, the plurality of semiconductor light emitting devices include first semiconductor light emitting elements emitting a first color and second semiconductor light emitting devices emitting a second color, and the semiconductor light emitting devices emitting the same color are at least in adjacent positions. It can be arranged in two rows. The semiconductor light emitting device disposed in any one of the at least two columns and the semiconductor light emitting device disposed in the other may be electrically connected to different electrode lines spaced a predetermined distance apart.

In one embodiment, the plurality of semiconductor light emitting devices may include light emitting devices that emit R, G, and B, respectively. The semiconductor light emitting devices emitting any one color of R, G, and B may be arranged in two adjacent rows. In this case, one pixel may be formed of a total of six semiconductor light emitting devices (R: 2, G: 2, B: 2). This is to prepare for any one light emitting device losing its light emitting ability.

In this case, the semiconductor light emitting elements included in the same pixel and emitting the same color may be connected to the same electrode line, but the present invention increases the number of electrode lines to subdivide the area through which light can pass. Through this, the present invention can subdivide the position where the partition wall can be formed.

Even in the case of forming the partition through the structures of FIGS. 12 to 18, the amount of light emitted from the lower side of the substrate should be greater than the amount of light emitted from the upper side of the substrate.

Referring to (a) of FIG. 19, when the light amount of light irradiated from the lower side of the substrate is smaller than the light amount of light irradiated from the upper side of the substrate, even if the total light amount of irradiated light is increased, the width of the partition portion is farther from the substrate. An increasing structure is formed.

On the contrary, referring to FIG. 19B, when the amount of light emitted from the lower side of the substrate is greater than the amount of light emitted from the upper side of the substrate, the width of the partition wall portion may be distant from the substrate regardless of the amount of light emitted. A decreasing structure is formed as it increases.

Since the partition wall portion according to the present invention has an excellent light-shielding ability because all regions are formed to have a reference width or more, and reflects light emitted from the semiconductor light emitting device to the upper side of the substrate, it is possible to increase the light extraction efficiency of the display device.

The display device using the semiconductor light emitting device described above is not limited to the configuration and method of the above-described embodiments, and the above embodiments may be configured by selectively combining all or part of each embodiment so that various modifications can be made. It might be.

Claims (10)

Board;
A plurality of semiconductor light emitting elements formed and disposed on the substrate;
A first electrode disposed on the substrate and electrically connected to the semiconductor light emitting elements under the semiconductor light emitting element;
A second electrode electrically connected to the semiconductor light emitting elements above the semiconductor light emitting element; And
The semiconductor light emitting element is disposed on the upper side, and includes a plurality of partition walls disposed between the semiconductor light emitting elements,
The substrate is made of a light transmissive material,
A display device, characterized in that the width of the partitions becomes narrower as it moves away from the substrate. According to claim 1,
The second electrode has a plurality of holes, characterized in that the display device. According to claim 2,
The plurality of holes are formed in a position overlapping the partition wall display device. According to claim 1,
The plurality of semiconductor light emitting devices are arranged in a plurality of rows,
The first electrode is composed of a plurality of electrode lines,
A display device characterized in that the semiconductor light emitting elements included in any one of the plurality of columns and the semiconductor light emitting elements included in the other one of the plurality of columns are electrically connected to different electrode lines. The method of claim 4,
A plurality of electrode lines are arranged to be spaced a predetermined distance,
The partition wall portion is a display device, characterized in that disposed between the electrode lines. The method of claim 4,
The semiconductor light emitting devices include first semiconductor light emitting elements emitting a first color and second semiconductor light emitting devices emitting a second color,
A semiconductor light emitting device that emits the same color is a display device, characterized in that arranged in at least two rows at adjacent positions. The method of claim 6,
A display device, characterized in that the semiconductor light emitting device disposed in any one of the at least two columns and the semiconductor light emitting device disposed in the other are electrically connected to different electrode lines arranged at a predetermined distance. delete delete delete

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